High pressure fuel delivery systems utilize a common rail (also known as a high pressure fuel rail, common rail, or accumulator) to accumulate and distribute fuel to fuel injectors at high-pressure while minimizing pressure fluctuations among the injectors. The high pressure fuel rail can be a single tube-like structure from which fuel is supplied to multiple injectors and functions as an accumulator to allow for precise control of high-pressure injection of fuel by an engine control unit (ECU) into the cylinders of an internal combustion engine at timing that is independent from the engine speed. Such high pressure fuel delivery systems, however, are susceptible to leakage from the high pressure fuel line or elsewhere in the delivery system. If fuel leakage occurs, the leaking fuel can spray onto high temperature surfaces of an engine and cause a fire. To safely deliver fuel in high pressure systems, modern fuel systems include measures to contain fuel leaks that may occur. For example, marine agency requirements such as the International Convention for the Safety of Life at Sea (SOLAS) treaty require double-walled fuel lines to prevent the likelihood of fire on a commercial marine vessel. These double-walled fuel lines must include a gap between the inner and outer walls to allow any fuel leaked from the inner wall to be detected by a fuel sensor while being contained by the outer wall.